MEP005A no start fuel system issues

[jinlanli]

Hello, been working on this problem for a while. Engine not starting-no fuel to injectors. Injection pump had a frozen fuel shutoff. Removed top of injection pump and got fuel shut off freed up. Now that the fuel shutoff is working-still no fuel to injectors. A problem I noticed is when I operate the fuel pumps, fuel is being pumped out on the return line. Fuel lines are disconnected at injection pump, the return fuel line that goes to day tank, pumps fuel out when you engage fuel pumps. Why is there fuel being pumped back to injection pump on the return line? The solenoid is not powered as far as I can tell. Only two wires on solenoid, and they connect to a block. When checking for voltage at solenoid terminals, there is none. Brand new on this site and had a difficult time just trying to figure out how to send a message. Lord knows how I am to find a response to these questions on this site. The tee fitting on top of injection pump for return fuel does not have a check valve. Is it supposed to have a check valve? I will go back to work on this monstrosity by trying to get at the day tank floats to see if they are stuck and preventing return fuel solenoid from working. Perhaps I will get lucky. Any suggestions on what the problem is will be appreciated.

 

[Ray70]

If I follow you correctly you are curious as to why you are seeing fuel in the return lines with the machine not running?
If so, this is normal, the return lines and supply line to the IP are connected together.
The base of the Tee fitting coming out of IP top cover should have a glass ball check valve in it, however someone probably removed it at some point.
That check valve missing will not cause the machine to not run, but could cause the lines to drain back over time if the machine sits a long time.
Regarding your not running issue, if the machine has sat a long time and the fuel solenoid was stuck, there is a good possibility you have other problems within the IP itself. The plungers in the head tend to get stuck in the "compressed" position. The governor weight basket drive coupling also tends to deteriorate and fall apart. small bits of black rubber in the body of the IP is a sure sign the drive coupler is falling apart.

 

[Guyfang]

Ray, he may not know that the glass ball is IN the "T". Lots of people expect to see a check valve below or above the "T". The first time I looked for it, I did.

Have you ever seen this set run right?
Have you downloaded the TM's and at least read to operators portion?
Do you have 24 VDC at the IP shut off solenoid?

 

[jinlanli]

The check valve ball is in the top cover of the injection pump, not in the tee fitting. The check valve is there, and it moves when pressing on it. I suspect you are correct regarding stuck pistons in the head assembly. MEP005a manufactured 1989--I bought at auction--perhaps a mistake as seller never tried to see if engine ran. Now I have it. The fuel shut off in the injection pump was stuck but freed it up with PB Blaster. That is now working fine, but still no fuel to injectors. When I found the stuck fuel shutoff, I thought I had the problem solved. I guess not. How to you free up the stuck pistons in the head assembly?

 

[jinlanli]

Ray, he may not know that the glass ball is IN the "T". Lots of people expect to see a check valve below or above the "T". The first time I looked for it, I did.

Have you ever seen this set run right?
Have you downloaded the TM's and at least read to operators portion?
Do you have 24 VDC at the IP shut off solenoid?

24 volt at fuel solenoid battle short on and run---when starting with battle short off---24 volt to solenoid

 

[jinlanli]

when I took injector pump cover off, I verified that fuel solenoid worked when applied 24 volt

 

[Ray70]

Removing and rebuilding the IP is the only way I know of to free up stuck plungers.
While you're in there upgrade to the 1 piece steel weight basket and coupler instead of the OE rubber coupler.
They are available on Ebay for around $75 or maybe $125 for a rebuild kit with the steel coupler basket included.
I don't think there is any good way to free up the plungers by soaking the internals etc. because there's no way to apply air pressure or anything from outside the pump to force the 2 plungers to pop outward.